UPDATE 2-US FDA eyes possible risk with Novartis iron drug

* No conclusions drawn yet, agency says

* Patients with bone disorder may have higher risk (Adds company comment, background on drug, shares)

WASHINGTON, Sept 25 (Reuters) - U.S. health officials are looking into whether patients with a certain bone marrow disorder are more at risk for death and serious complications with Novartis AG's NOVN.VXNVS.N drug Exjade.

Those with myelodysplastic syndrome (MDS) may have a higher risk of kidney failure, potentially fatal bleeding and death with use of the drug, which helps regulate iron levels in patients who receive regular blood transfusions, the U.S. Food and Drug Administration said on Friday.

In a notice on its website, the agency said it was investigating reported complications in patients using the drug but that several factors make it difficult to draw any conclusions without a closer look.

Patients who had serious side effects were typically older, the FDA said. They also may have had other medical problems which could be a factor, the agency said. Problems seemed fewer in younger patients with other chronic anemia conditions.

Novartis, in a statement, said it was working with the FDA “to further review and clarify the population of MDS patients most appropriate for treatment with Exjade.” It is working with the FDA over how to present the information on the drug’s label.

The FDA said it would issue its final conclusions when it concluded its analysis of all the data. In the meantime, patients should talk to their doctors, it said.

Exjade has already been linked to other, potentially fatal side effects such as kidney and liver failure, among other conditions, according to the agency.

Shares of Novartis closed up 9 cents at $48.86 on the New York Stock Exchange. (Reporting by Susan Heavey; Editing by Carol Bishopric)